The Influence of Secondary Interactions during the Formation of Polyelectrolyte Multilayers: Layer Thickness, Bound Water and Layer Interpenetration
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- 作者：Manesh Gopinadhan ; Oxana Ivanova ; Heiko Ahrens ; Jens-Uwe Gü ; nther ; Roland Steitz ; Christiane A. Helm
- 刊名：Journal of Physical Chemistry B
- 出版年：2007
- 出版时间：July 26, 2007
- 年：2007
- 卷：111
- 期：29
- 页码：8426 - 8434
- 全文大小：483K
- 年卷期：v.111,no.29(July 26, 2007)
- ISSN：1520-5207
文摘
With X-ray and neutron reflectivity, the structure and composition of polyelectrolyte multilayers from poly(allyl amine) (PAH) and poly(styrene sulfonate) (PSS) are studied as function of preparation conditions (saltconcentration and solution temperature, T). The onset of a temperature effect occurs at 0.05 M NaCl (Debyelength ~ 1 nm). At 1 M salt, the film thickness increases by a factor of 3 on heating the deposition solutionfrom 5 to 60 
C. The PAH/PSS bilayer thickness is independent of the kind of salt (NaCl or KCl), yet itscomposition is different (more bound water for NaCl). At low T, the internal roughness is 33% of the bilayerthickness; it increases to 60% at high T. The roughening is accompanied by a total loss of bound water. Atwhich temperature the roughening starts is a function of the kind of salt (50 C for NaCl and 35 C for KCl).The strong temperature dependence and the eventual loss of bound water molecules may be attributed to thehydrophobic force; however, there is an isotope effect, since the loss of bound water is less pronounced inthe deuterated layers.
C. The PAH/PSS bilayer thickness is independent of the kind of salt (NaCl or KCl), yet itscomposition is different (more bound water for NaCl). At low T, the internal roughness is 33% of the bilayerthickness; it increases to 60% at high T. The roughening is accompanied by a total loss of bound water. Atwhich temperature the roughening starts is a function of the kind of salt (50 C for NaCl and 35 C for KCl).The strong temperature dependence and the eventual loss of bound water molecules may be attributed to thehydrophobic force; however, there is an isotope effect, since the loss of bound water is less pronounced inthe deuterated layers.